[AntiGuv]

No. There are those aberrations (i.e. horse & donkey) where different species can produce viable offspring. My point, however, is that when two populations can never produce viable offspring via natural means, then they are invariably of different species. This means that if a coelocanth of today has drifted far enough away from a coelocanth of 100 million years ago that they would be unable to mate, then the two are genotyped as different species even if their phenotypes are virtually identical.

[gore3000]

This means that if a coelocanth of today has drifted far enough away from a coelocanth of 100 million years ago that they would be unable to mate, then the two are genotyped as different species even if their phenotypes are virtually identical.

That is exactly why speciation is totally insufficient to prove that evolution has occurred. If there are no changes in functioning, in abilities, in complexity, then no evolution has occurred because evolution requires increased functioning, increased abilities and increased complexity in order for man to have descended from bacteria.

[AndrewC]

My point, however, is that when two populations can never produce viable offspring via natural means, then they are invariably of different species.

So a eunuch is a different species?

And in case you didn't know it, llamas and camels, which diverged 30 million years ago, can produce viable offspring which may be fertile.